Process for eliminating marks formed in the roller printing of textile fabrics by the accidental spreading of discharge agent beyond the engraved areas of the printing roller



Patented Oct. 15, 1 935.

PnooEssZron ELIMINATING MARKS FORMED IN THE ROLLER PRINTING F TEXTILE {FABRICS BY THE, ACCIDENTAL SPREADMING. 0F. DISCHARGE AGENT BE- YOND 'rna ENGRAVED AREAS OF THE PRINTING ROLLER Fred Baumann, Glen Rock, N. J., assignor to Alexander Chemical Company, a corporation of New Jersey No Drawing. Application January 20, 193i, Serial No. 652.7 72

12 Claims.

The printing of designs in color on textile fabrics is ordinarily carried out by running the fabric between two rollers. One of the rollers carries upon its surface engraved areas corresponding to those components of the complete design which are to be printed in a single color. The color to be transferred to the fabric may, for example, consist of a fluid mixture of pigments with water and so-called printing gum. This color is applied to the surface of the printing roller as it rotates either by means of a second parallel roller which makes contact with the printing roller, or by running the lower edge of the printing roller in a trough containing the color. In either case, the excess of color is scraped off by the doctor blade as the roller rotates leaving color in the engraved areas only of that .part of the printing roller which has passed the doctor knife. The printing roller after passing the doctor knife contacts with the moving band of fabric. As the printing roller passes over the fabric, the pressure between the printing roller and the press roller forces the fabric into the engraved areas, thereby driving the color into the fabric. In the usual roller printing machine the press roller is relatively large in diameter and a number of printing rollers may be employed in succession, each of which applies to the fabric all of the components of the design which are printed in a single color.

Where a uniform background is required, this may be applied to the fabric in a preliminary dyeing operation, either in the yarn or in the piece. The color so applied to the fabric may be hereinafter referred to as the base color of the fabric or more briefly to the base color;

In many cases it is necessary or desirable. to eliminate or reduce the base color in the area to which the new color is applied by the printing .roller in order to eliminate or reduce the harmful efiect of the base color on the new. This is ordinarily accomplished by admixing a discharge with the fluid mixture of gum and pigments forming the new color before the same is applied to the printing roller. The new color is so selected that it is not harmfully affected by'the discharge, and the discharge operates to partly or completely eliminatethe base color in the area to which it is applied. The discharge may contain sodium sulphoxylate or a derivative of sodium hydrosulphite and formaldehyde, or someother reducing agent of a similar character. After printing, the fabric is ordinarily subjected to the so-called steaming or aging process by means of which the action of the reducingagent on the base color is driven to completion.

It may, of course, under certain circumstances be desirable to apply such a discharge agent to the fabric, preferably in fluid admixture with a suitable gum, even though a new color is not simultaneously applied, and where the sole effect desired is the reduction or elimination of the base color over a predetermined area.

It not infrequently happens, however, in either case, that owing to a defect "in the printing roller or the doctor blade some of the discharge is 10 smeared or tracked over the smooth portions of the printing roller, thereby esulting ultimately in serious damage to the fa ric. Failure of the doctor knife to make perfect contact with the printing roller over the entire length of the same may, for example, leave a smear of discharge on the printing roller which shows up as a streak running longitudinally along the entire length of the printed fabric.

I have found that such streaks, and in general marks caused by the spreading of the discharge beyond the engraved areas of the printing roller, may be entirely eliminated without damage to the color imparted to the fabric by the engraved areas of the printing roller by. the application to the fabric, after printing and before aging, of

- hydrogen peroxide preferably in aqueous solution.

by the printing roller are relatively delicate, I find it of further advantage to admix the hydrogen peroxide or aqueous hydrogen peroxide solution before application with a suitable gum, such as gum tragacanth, or the usual so-called textile printing gum, starch or dextrin may be similarly employed with the said hydrogen peroxide solution.

In accordance with my process, immediately after printing a piece of fabric a short section of the same iscut off and separately aged to bring out any tracks or streaks which may have been formed during printing by the undesired spreading of the discharge agent beyond the engraved areas of the printing roller, and to permit the operator to determine whether any such streaks the other.

or tracks exist. If any are found in the aged section, the remainder of the piece is treated with hydrogen peroxide.

This may be carried out by running the fabric between two rollers, to'one of which there is continuously applied the hydrogen peroxide, and for this purpose I may utilize the usual roller type printing machine. When so utilizing the printing machine, however, no color is applied to the fabric. One or more rollers are employed, and the said rollers are preferably engraved with a multiplicity of very fine lines covering the surface of the same. The lower edge of said roller or rollers will run in a trough containing the hydrogen peroxide either anhydrous or in solution as aforesaid, and the doctor knife will operate to remove any excess of the same lying above the surface of said roller or rollers. The reagent retained in the fine engraved lines will be applied to the fabric when the fabric is run through the printing machine.

Instead of employing rollers engraved as aforesaid, rollers with a true cylindrical surface may be employed, and in this case the doctor knife is adjusted to leave only a thin film of the peroxide solution adhering to the roller, and this film is in turn transferred to the surface of the fabric as the roller rotates.

For the purpose of applying-a film of the reagent to the textile fabric, I may alternatively employ a two roll mangle. This consists of two rollers with parallel axes mounted one above The lower roller rotates in a trough containing the reagent. This roller may be formed with a true cylindrical surface, in which event the doctor knife is adjusted to leave a thin film of the reagent adhering to the surface of the roller, or may alternatively be formed with a multiplicity of fine lines engraved in the surface of the roller, in which event the doctor knife is adjusted to remove the excess of reagent over that retained in the fine engraved lines. The textile fabric is fed progressively into the bight of the rollers and the film of the reagent is thereby transferred to the surface of the fabric.

A further alternative and in many cases preferred method comprises the employment of a three roll mangle. This consists of three rollers with parallel axes mounted one above the other. The lowest roller runs in a trough containing the reagent and operates thereby to transfer a thin film of the reagent to the second or middle roller. The fabric is fed into the bight between the middle and top roller, and thereby continuously picks up the film of reagent from the surface of the middle roller.

Where smooth rollers are employed, they may be formed either of rubber or of a metal, of. copper, and where engraved rollers are employed, they are preferably formed of a metal such as copper.

After this step of the process, the fabric is aged in the usual way, and after aging will be found to be entirely free from the undesired tracks or streaks. In many cases, the colors of the design will be found to present an enhanced brilliance or improved appearance over that which would normally result from the combined action of the printing and aging processes.

The foregoing specific description is for purposes of illustration and not of limitation, and

.it is therefore my intention that the invention be limited only by the appended claims or their equivalents.

I claim:

1. In the roller printing of textile fabrics wherein a reduction discharge agent is applied to the fabric by means of the engraved areas of a printing roller, the process of eliminatin 5 marks accidentally resulting from discharge agent carried by the smooth surfaces of the roller when riding over the fabric, which comprises applying to the goods after printing hydrogen peroxide.

2. In the roller printing of textile fabrics wherein a reduction discharge agent is applied to the fabric by means of the engraved areas of a printing roller, the process of eliminating marks accidentally resulting from discharge agent carried by the smooth surfaces of the roller when riding over the fabric, which comprises applying to the goods after printing an aqueous solution of hydrogen peroxide.

3. Process according to claim 2, in which the aqueous solutio v of hydrogen peroxide contains 7 from 1/10 to 30% by weight of hydrogen peroxide in relation to the water present.

4. In the roller printing of textile fabrics wherein a reduction discharge agent is applied by means of the engraved areas of a printing roller, the process of eliminating marks accidentally resulting from discharge agent carried by the smooth surfaces of the printing roller when riding over the fabric, which comprises applying to the goods after printing a superficial film of hydrogen peroxide.

5. In the roller printing of textile fabrics wherein a reduction discharge agent is applied by means of the engraved areas of a printing roller, the process of eliminating marks accidentally resulting from discharge agent carried by the smooth surfaces of the printing roller when riding over the fabric, which comprises applying to the goods after printing a superficial film of an aqueous solution of hydrogen peroxide.

6. Process according to claim 5, in which the aqueous solution of hydrogen peroxide contains from 1/10 to 30% by weight of hydrogen peroxide in relation to the water present.

7. In the roller printing of textile fabrics wherein a reduction discharge agent is applied over a base color by means of the engraved areas of a printing roller, the process of eliminating marks accidentally resulting from discharge agent carried by the smooth surfaces of the roller when riding over the fabric, which comprises applying to the goods after printing hydrogen peroxide in fluid admixture with a gum.

8. In the roller printing of textile fabrics wherein a reduction discharge agent is applied over a base color by means of the engraved areas of a printing roller, the process of eliminating marks accidentally resulting from discharge agent carried by the smooth surfaces of the roller when riding over the fabric, which comprises applying to the goods after printing an aqueous solution of hydrogen peroxide in fluid admixture with a gum.

9. Process according to claim 8, in which the aqueous solution of hydrogen peroxide contains from 1/ 10 to 30% of hydrogen peroxide in relation to the water present.

10. In the roller printing of textile fabrics wherein a reduction discharge agent is applied by means of the engraved areas of a printing roller, the process of eliminating marks acci-' dentally resulting from discharge agent carried 75 by the smooth surfaces of the printing roller when riding over the fabric, which comprises applying to the goods after printing as a superficial film hydrogen peroxide in fluid admixture with a gum.

11. In the roller printing of textile fabrics wherein a reduction discharge agent is applied by means of the engraved areas of a printing roller, the process of eliminating marks accidentally resulting from discharge agent carried by the smooth surfaces of the printing roller when riding over the fabric, which comprises applying to the goods after printing as a superficial film an aqueous solution of hydrogen peroxide in fluid admixture with a gum.

12. Process according to claim 11, in which the aqueous solution of hydrogen peroxide contains from 1/10 to 30% of hydrogen peroxide in rela- 7 tion to the water present.

FRED BAUMANN. 

